The present invention relates to a cutting toolholder for a bar peeling operation, including a rotary cutter head that carries a plurality of toolholders each equipped with one or several inserts of cemented carbide or similar wear resistant material.
Bar peeling is a method by which an elongated bar is fed through a rotary cutter head equipped with a plurality of cutting tool distinctly provided around the periphery of the cutter head for the purpose of removing from the bar a thin layer of, e.g., millscale, surface cracks, etc., that result from the hot rolling of such bars or tubes. In order to achieve the best results regarding tolerances and surface finish, two different types of inserts are usually combined in the same holder.
It is desirable to be able to make a fine adjustment of the exact radial position or such inserts (normally 4). Normally, the adjustment range is on the order of 0.01 mm. This adjustment may be accomplished by grinding the supporting bevel face of the insert after the insert has been put into its location in the holder. The disadvantage of this method is that grinding the insert also removes the surface layer that normally has been deposited on the surface of the insert, e.g., by CVD-technique, for the purpose of increasing the lifetime of the insert. Hence, before starting to use the insert, the increased performance ability of the insert achieved by the layer deposited on the surface is taken away by grinding. Further, it is almost impossible to make exactly the same amount or grinding on all of the inserts of such a rotary cutter head of a bar peeling machine. Any resulting inaccuracy additionally impairs the precision of the tools.
In view thereof, it is a purpose of this invention to provide a toolholder in which the inserts can be maintained in their positions whilst being adjustable with other means.
It is another purpose of this invention to provide a toolholder that is equipped with means that will enable radial adjustment in a relatively simple manner without having to provide separate fixtures for the inserts and holders during the adjustment. It is a further purpose of the present invention to provide such adjustment means that can accomplish accurate fine adjustments without removing the toolholder from its location in the bar peeling machine.
The present invention provides a mechanism for fine adjustment of the radial position of the cutting edge with a very good precision. It is important to be able to make such radial adjustment without affecting the pre-adjusted axial position of the same insert.
These and other objects of the invention are achieved by a cutting tool for bar peeling which comprises a rotatable cutter head equipped with a plurality of toolholders around its periphery, each of which is carrying at least one cutting insert of wear resistant material. Each of the cutting tools carried by the toolholder is radially adjustable by longitudinal displacement of a wedge element.